Semiconductor structure and manufacturing method thereof

ABSTRACT

A semiconductor structure includes a first substrate including a cavity extended into the first substrate, a device disposed within the cavity, a first dielectric layer disposed over the first substrate and a first conductive structure surrounded by the first dielectric layer, and a second substrate including a second dielectric layer disposed over the second substrate and a second conductive structure surrounded by the second dielectric layer, wherein the first conductive structure is bonded with the second conductive structure and the first dielectric layer is bonded with the second dielectric layer to seal the cavity.

BACKGROUND

Electronic equipment involving semiconductive devices are essential for many modern applications. The semiconductive device has experienced rapid growth. Technological advances in materials and design have produced generations of semiconductive devices where each generation has smaller and more complex circuits than the previous generation. In the course of advancement and innovation, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometric size (i.e., the smallest component that can be created using a fabrication process) has decreased. Such advances have increased the complexity of processing and manufacturing semiconductive devices.

Micro-electro mechanical system (MEMS) devices have been recently developed and are also commonly involved in electronic equipment. The MEMS device is micro-sized device, usually in a range from less than 1 micron to several millimeters in size. The MEMS device includes fabrication using semiconductive materials to form mechanical and electrical features. The MEMS device may include a number of elements (e.g., stationary or movable elements) for achieving electro-mechanical functionality. For many applications, MEMS device is electrically connected to external circuitry to form complete MEMS systems. Commonly, the connections are formed by wire bonding. MEMS devices are widely used in various applications. MEMS applications include motion sensor, gas detectors, pressure sensors, printer nozzles, or the like. Moreover, MEMS applications are extended to optical applications, such as movable mirrors, and radio frequency (RF) applications, such as RF switches or the like.

As technologies evolve, design of the devices becomes more complicated in view of small dimension as a whole and increase of functionality and amounts of circuitries. Numerous manufacturing operations are implemented within such a small and high performance semiconductor device. The manufacturing of the semiconductor device in a miniaturized scale becomes more complicated. The increase in complexity of manufacturing may cause deficiencies such as high yield loss, poor reliability of the electrical interconnection, warpage, etc. Therefore, there is a continuous need to modify structure and manufacturing method of the devices in the electronic equipment in order to improve the device performance as well as reduce manufacturing cost and processing time.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 is a schematic view of a semiconductor structure in accordance with some embodiments of the present disclosure.

FIG. 1A is a schematic top view of a semiconductor structure in accordance with some embodiments of the present disclosure.

FIG. 2 is a schematic view of a semiconductor structure in accordance with some embodiments of the present disclosure.

FIG. 3 is a flow diagram of a method of manufacturing a semiconductor structure in accordance with some embodiments of the present disclosure.

FIGS. 3A-3D are schematic views of manufacturing a semiconductor structure by a method of FIG. 3 in accordance with some embodiments of the present disclosure.

FIG. 4 is a flow diagram of a method of manufacturing a semiconductor structure in accordance with some embodiments of the present disclosure.

FIGS. 4A-4I are schematic views of manufacturing a semiconductor structure by a method of FIG. 4 in accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

An electronic equipment can include multiple MEMS sensors, and those sensors can be integrated onto a semiconductive chip in recent generation of MEMS applications. For example, motion or inertial sensors are used for motion-activated user interfaces in consumer electronics such as smartphones, tablets, gaming consoles, and in automotive crash detection systems. To capture a complete range of movements within a three-dimensional space, motion sensors often utilize an accelerometer and a gyroscope in combination. The accelerometer detects linear movement, and the gyroscope detects angular movement. In addition, a magnetic sensor such as electronic compass is also integrated onto the chip for navigation. The magnetic sensor can determine a direction of an external magnetic field. To meet consumer's demand for low cost, high quality, and small device footprint, multiple sensors are integrated together on a same substrate.

A MEMS package is fabricated by various processes. The MEMS package includes a substrate eutectically bonded with another substrate and a MEMS device enclosed by a cavity of one of the substrates. The eutectic bonding of the substrates has to be performed under a high temperature (for example, greater than 400° C.) and requires application of a large compressive force (for example, greater than 30,000N) on the substrates during the bonding. Such a high temperature or a large compressive force would cause thermal internal stress to the MEMS package, cracks in the substrates or damage on electrical interconnects in the substrates. As a result, reliability and performance of the MEMS package would be adversely affected.

The present disclosure is directed to a semiconductor structure including a substrate bonded with another substrate. The substrates are bonded by directly bonding conductive structures respectively disposed over the substrates and directly bonding dielectric layers respectively disposed over the substrates. Such bonding of the substrates can be performed under a low temperature (for example, lower than 250° C.), and the substrates can be bonded without application of a compressive force on the substrates. Therefore, the semiconductor structure would not be damaged by a high temperature or a large force. Furthermore, since the semiconductor structure would not under a high temperature during, a device such as an accelerometer, which would be easily deteriorated by high temperature (for example, greater than 300° C.), would not be affected by high temperature and thus can be formed over the substrates before the bonding operations. Other embodiments are also disclosed.

FIG. 1 is a schematic cross sectional view of a semiconductor structure 100 in accordance with some embodiments of the present disclosure. In some embodiments, the semiconductor structure 100 is configured for sensing various characteristics such as motion, movement, magnetic field, pressure or etc. or combination thereof. In some embodiments, the semiconductor structure 100 includes a first substrate 101 and a second substrate 102 stacked over the first substrate 101. It will be appreciated that the semiconductor structure 100 may include one or more substrates stacking over another.

In some embodiments, the semiconductor structure 100 includes the first substrate 101. In some embodiments, the first substrate 101 may include several circuitries and one or more active elements such as transistors etc. disposed over or in the first substrate 101. In some embodiments, the circuitries formed over or in the first substrate 101 may be any type of circuitry suitable for a particular application. In some embodiments, the first substrate 101 is a MEMS substrate.

In some embodiments, the first substrate 101 includes a first substrate layer 101 a. In some embodiments, several circuitries or metallic structures are disposed over or within the first substrate layer 101 a. In some embodiments, the first substrate layer 101 a includes semiconductive materials such as silicon or other suitable materials. In some embodiments, the first substrate layer 101 a is a silicon substrate or silicon wafer. In some embodiments, transistors, capacitors, resistors, diodes, photo-diodes and/or the like are disposed over the first substrate layer 101 a.

In some embodiments, the first substrate 101 includes a first dielectric layer 101 b disposed over the first substrate 101 or the first substrate layer 101 a. In some embodiments, the first dielectric layer 101 b is conformal to a surface of the first substrate layer 101 a. In some embodiments, the first dielectric layer 101 b includes dielectric material such as oxide, nitride, silicon dioxide, silicon nitride, silicon oxynitride, silicon carbide, polymer or the like.

In some embodiments, the first substrate 101 includes a first conductive structure 101 c surrounded by the first dielectric layer 101 b. In some embodiments, the first conductive structure 101 c is extended and disposed within the first dielectric layer 101 b. In some embodiments, the first conductive structure 101 c is electrically connected with the circuitry in the first substrate layer 101 a. In some embodiments, the first conductive structure 101 c is laterally extended over the first substrate layer 101 a and within the first dielectric layer 101 b. In some embodiments, the first conductive structure 101 c is laterally extended along a periphery 101 f of the first substrate 101, over the first substrate layer 101 a and within the first dielectric layer 101 b.

In some embodiments, the first conductive structure 101 c is in a partially closed loop or in a ring shape. In some embodiments, the first conductive structure 101 c is a bond ring. In some embodiments, the first conductive structure 101 c is a sealing ring for sealing the cavity 101 g. In some embodiments, the first conductive structure 101 c includes conductive or metallic material such as gold, silver, copper, nickel, tungsten, aluminum, tin and/or alloys thereof. In some embodiments, the first dielectric layer 101 b includes a top surface 101 d, and the first conductive structure 101 c includes a top surface 101 e, and the top surface 101 d of the first dielectric layer 101 b is at a same level as the top surface 110 e of the first conductive layer 101 c.

In some embodiments, the first substrate 101 includes a cavity 101 g extended into the first substrate 101 or the first substrate layer 101 a. In some embodiments, the cavity 101 g is extended from the first dielectric layer 101 b to the first substrate layer 101 a. In some embodiments, the cavity 101 g is defined by the first dielectric layer 101 b to the first substrate layer 101 a. In some embodiments, the cavity 101 g is recessed into the first dielectric layer 101 b and the first substrate layer 101 a.

In some embodiments, the first substrate 101 includes a device 101 h disposed within the cavity 101 g. In some embodiments, the device 101 h is displaceable or movable relative to the first substrate layer 101 a and the first dielectric layer 101 b. In some embodiments, the device 101 h is configured for sensing one or more characteristics such as motion, movement, pressure or etc. or combination thereof. In some embodiments, the device 101 h includes a proof mass for reacting with a motion along a plane. In some embodiments, the device 101 h is a MEMS device. In some embodiments, the device 101 h is an accelerometer for measuring linear acceleration. In some embodiments, the device 101 h is a gyroscope for measuring angular velocity.

In some embodiments, the semiconductor structure 100 includes the second substrate 102. In some embodiments, the second substrate 102 may include several circuitries and one or more active elements such as transistors etc. disposed over or in the second substrate 102. In some embodiments, the circuitries formed over or in the second substrate 102 may be any type of circuitry suitable for a particular application. In some embodiments, the second substrate 102 is a CMOS substrate. In some embodiments, the second substrate 102 includes several CMOS components or devices.

In some embodiments, the second substrate 102 is disposed opposite to the first substrate 101. In some embodiments, the second substrate 102 is disposed over or stacked over the first substrate 101. In some embodiments, the first substrate 101 is aligned with the second substrate 102. In some embodiments, the periphery 101 f of the first substrate 101 is vertically aligned with a periphery 102 f of the second substrate 102. In some embodiments, the second substrate 102 includes a second substrate layer 102 a. In some embodiments, several circuitries or metallic structures are disposed over or within the second substrate layer 102 a. In some embodiments, the second substrate layer 102 a includes semiconductive materials such as silicon or other suitable materials. In some embodiments, the second substrate layer 102 a is a silicon substrate or silicon wafer. In some embodiments, transistors, capacitors, resistors, diodes, photo-diodes and/or the like are disposed over the second substrate layer 102 a. In some embodiments, the second substrate layer 102 a has similar configuration as the first substrate layer 101 a described above or illustrated in FIG. 1.

In some embodiments, the second substrate 102 includes a second dielectric layer 102 b disposed over the second substrate 102 or the second substrate layer 102 a. In some embodiments, the second dielectric layer 102 b is disposed opposite to the first dielectric layer 101 b. In some embodiments, the second dielectric layer 102 b is conformal to a surface of the second substrate layer 102 a.

In some embodiments, at least a portion of the second dielectric layer 102 b is bonded with a portion of the first dielectric layer 101 b. In some embodiments, at least a portion of the second dielectric layer 102 b is directly bonded or interfaced with a portion of the first dielectric layer 101 b. In some embodiments, the cavity 101 g is enclosed by the first substrate 101 and the second dielectric layer 102 b. In some embodiments, the cavity 101 g is enclosed by the first substrate layer 101 a, the first dielectric layer 101 b and the second dielectric layer 102 b.

In some embodiments, the first dielectric layer 101 b is aligned with the second dielectric layer 102 b. In some embodiments, the second dielectric layer 102 b includes a top surface 102 d interfaced and aligned with the top surface 101 d of the first dielectric layer 101 b. In some embodiments, a portion of the first dielectric layer 101 b is bonded with a portion of the second dielectric layer 102 b to seal the cavity 101 g. In some embodiments, the cavity 101 g is sealed or is hermetic. In some embodiments, the cavity 101 g is in vacuum or is at a gas pressure lower than about 1 atmospheric pressure (atm).

In some embodiments, the second dielectric layer 102 b includes dielectric material such as oxide, nitride, silicon dioxide, silicon nitride, silicon oxynitride, silicon carbide, polymer or the like. In some embodiments, the second dielectric layer 102 b includes same material as or different material from the first dielectric layer 101 b. In some embodiments, the second dielectric layer 102 b has similar configuration as the first dielectric layer 101 b described above or illustrated in FIG. 1.

In some embodiments, the second substrate 102 includes a second conductive structure 102 c surrounded by the second dielectric layer 102 b. In some embodiments, the second conductive structure 102 c is extended and disposed within the second dielectric layer 102 b. In some embodiments, the second conductive structure 102 c is electrically connected with the circuitry in the second substrate layer 102 a. In some embodiments, the second conductive structure 102 c is laterally extended over the second substrate layer 102 a and within the second dielectric layer 102 b. In some embodiments, the second conductive structure 102 c is a part of a redistribution layer (RDL). In some embodiments, the second conductive structure 102 c is laterally extended along the periphery 102 f of the second substrate 102, over the second substrate layer 102 a and within the second dielectric layer 102 b. In some embodiments, a conductive via or conductive plug is disposed over and extended from the second conductive structure 102 c for signal routing. In some embodiments, an electrical signal from the second conductive structure 102 c can be picked from the second conductive structure 102 c through the conductive via or the conductive plug. In some embodiments, the conductive via or conductive plug extends through the second dielectric layer 102 b or the second substrate 102 a.

In some embodiments, the second conductive structure 102 c is in a partially closed loop or in a ring shape. In some embodiments, the second conductive structure 102 c is a bond ring. In some embodiments, the second conductive structure 102 c is a sealing ring for sealing the cavity 101 g. In some embodiments, the second conductive structure 102 c includes conductive or metallic material such as gold, silver, copper, nickel, tungsten, aluminum, tin and/or alloys thereof. In some embodiments, the second conductive structure 102 c includes same material as or different material from the first conductive structure 101 c. In some embodiments, the second conductive structure 102 c includes a top surface 102 e, which is at a same level as the top surface 102 d of the second dielectric layer 102 b.

In some embodiments, the second conductive structure 102 c is disposed over or opposite to the first conductive structure 101 c. In some embodiments, the first conductive structure 101 c is aligned with the second conductive structure 102 c. In some embodiments, the top surface 101 e of the first conductive structure 101 c is interfaced and aligned with the top surface 102 e of the second conductive structure 102 c. In some embodiments, the first conductive structure 101 c is bonded with the second conductive structure 102 c. In some embodiments, at least a portion of the first conductive structure 101 c is directly bonded or interfaced with a portion of the second conductive structure 102 c. In some embodiments, the first conductive structure 101 c is bonded with the second conductive structure 102 c, such that the cavity 101 g is sealed or hermetic.

In some embodiments, the first conductive structure 101 c is complementary to the second conductive structure 102 c. In some embodiments, the first conductive structure 101 c is structurally complementary to the second conductive structure 102 c. In some embodiments, a dimension of the first conductive structure 101 c is similar to a dimension of the second conductive structure 102 c. In some embodiments, the top surface 101 e of the first conductive structure 101 c has similar dimension as the top surface 102 e of the second conductive structure 102 c.

In some embodiments, the first conductive structure 101 c is bonded with electrically connected with the second conductive structure 102 c, such that the first substrate 101 is integrated with the second substrate 102. In some embodiments, the circuitry of the first substrate 101 is electrically connected with the circuitry of the second substrate 102. In some embodiments, the first conductive structure 101 c or the second conductive structure 102 c is electrically connected with the circuitry disposed over the second substrate layer 102 a 102 or within the second dielectric layer 102 b. In some embodiments, the second conductive structure 102 c is electrically connected with the circuitry in the second dielectric layer 102 b through a via extending within the second dielectric layer 102 b. In some embodiments as shown in FIG. 1A (a top cross sectional view of the semiconductor structure 100), the first conductive structure 101 c or the second conductive structure 102 c is configured in a closed loop shape or an annular shape. In some embodiments as shown in FIG. 1A, more than one first conductive structure 101 c is configured and extended over the first substrate 101 a. In some embodiments, more than one second conductive structure 102 c is configured and extended over the first substrate 101 a. In some embodiments, the sealing of the cavity 101 g can be advanced or the protection of the device 101 h from moisture or contamination can be reinforced by increasing a number of loops of the first conductive structures 101 c or the second conductive structures 102 c.

FIG. 2 is a schematic cross sectional view of a semiconductor structure 200 in accordance with some embodiments of the present disclosure. In some embodiments, the semiconductor structure 200 is configured for sensing various characteristics such as motion, movement or etc. In some embodiments, the semiconductor structure 200 includes a first substrate 201, a second substrate 202, a dielectric layer 203, a conductive structure 204, a chamber 205 and a device 206 and an interface 207.

In some embodiments, the second substrate 202 is disposed opposite to the first substrate 201. In some embodiments, the second substrate 202 is stacked over the first substrate 201. It will be appreciated that the semiconductor structure 200 may include one or more substrates stacking over another. In some embodiments, the first substrate 201 is aligned with the second substrate 202.

In some embodiments, the first substrate 201 may include several circuitries and one or more active elements such as transistors etc. disposed over or in the first substrate 201. In some embodiments, the circuitries formed over or in the first substrate 201 may be any type of circuitry suitable for a particular application. In some embodiments, the first substrate 201 is a MEMS substrate. In some embodiments, the first substrate 201 includes semiconductive materials such as silicon or other suitable materials. In some embodiments, the first substrate 201 is a silicon substrate or silicon wafer. In some embodiments, the first substrate 201 has similar configuration as the first substrate layer 101 a of the semiconductor structure 100 described above or illustrated in FIG. 1.

In some embodiments, the second substrate 202 may include several circuitries and one or more active elements such as transistors etc. disposed over or in the second substrate 202. In some embodiments, the circuitries formed over or in the second substrate 102 may be any type of circuitry suitable for a particular application. In some embodiments, the second substrate 202 is a CMOS substrate. In some embodiments, the second substrate 202 includes several CMOS components or devices. In some embodiments, the second substrate 202 includes semiconductive materials such as silicon or other suitable materials. In some embodiments, the second substrate 202 is a silicon substrate or silicon wafer. In some embodiments, the second substrate 202 has similar configuration as the second substrate layer 102 a of the semiconductor structure 100 described above or illustrated in FIG. 1.

In some embodiments, the dielectric layer 203 is disposed between the first substrate 201 and the second substrate 202. In some embodiments, the dielectric layer 203 is bonded with the first substrate 201 and the second substrate 202. In some embodiments, the dielectric layer 203 is directly bonded or interfaced with a portion of the first substrate 201. In some embodiments, the dielectric layer 203 is directly bonded or interfaced with the second substrate 202. In some embodiments, the dielectric layer 203 is conformal to a surface of the first substrate 201 and a surface of the second substrate 202. In some embodiments, the dielectric layer 203 is aligned with the first substrate 201 and the second substrate 202. In some embodiments, a periphery of the first substrate 201 is aligned with a sidewall 203 c of the dielectric layer 203. In some embodiments, a periphery of the second substrate 202 is aligned with the sidewall 203 c of the dielectric layer 203.

In some embodiments, the dielectric layer 203 includes dielectric material such as oxide, nitride, silicon dioxide, silicon nitride, silicon oxynitride, silicon carbide, polymer or the like. In some embodiments, the dielectric layer 203 has similar configuration as the first dielectric layer 101 b or the second dielectric layer 102 b of the semiconductor structure 100 as described above or illustrated in FIG. 1.

In some embodiments, the conductive structure 204 is disposed within the dielectric layer 203. In some embodiments, the conductive structure 204 is surrounded by the dielectric layer 203. In some embodiments, the conductive structure 204 is laterally extended along the periphery 201 a of the first substrate 201 or the periphery 202 a of the second substrate 202. In some embodiments, the conductive structure 204 is a part of a circuitry of the semiconductor structure 200. In some embodiments, the conductive structure 204 is electrically connected with the circuitry of the first substrate 201 and the circuitry of the second substrate 202. In some embodiments, the conductive structure 204 is a part of a redistribution layer (RDL). In some embodiments, the conductive structure 204 is in a partially closed loop or in a ring shape. In some embodiments, the conductive structure 204 is a bond ring.

In some embodiments, the conductive structure 204 includes conductive or metallic material such as gold, silver, copper, nickel, tungsten, aluminum, tin and/or alloys thereof. In some embodiments, the conductive structure 204 has similar configuration as the first conductive structure 101 c or the second conductive structure 102 c of the semiconductor structure 100 as described above or illustrated in FIG. 1.

In some embodiments, the chamber 205 is extended from the first substrate 201 to the dielectric layer 203 and enclosed by the first substrate 201 and the dielectric layer 203. In some embodiments, a portion of the chamber 205 is protruded into the dielectric layer 203. In some embodiments, a portion of the chamber 205 is protruded into the first substrate 201. In some embodiments, the chamber 205 is a void inside the semiconductor structure 200. In some embodiments, the chamber 205 is sealed or is hermetic. In some embodiments, the chamber 205 is in vacuum or is at a gas pressure lower than about 1 atmospheric pressure (atm). In some embodiments, the chamber 205 has similar configuration as the cavity 101 g of the semiconductor structure 100 as described above or illustrated in FIG. 1.

In some embodiments, the device 206 is disposed within the chamber 205. In some embodiments, the device 206 is displaceable or movable relative to the first substrate 201, the second substrate 202 and the dielectric layer 203. In some embodiments, the device 206 is configured for sensing one or more characteristics such as motion, movement or etc. In some embodiments, the device 206 includes a proof mass for reacting with a motion along a plane. In some embodiments, the device 206 is a MEMS device. In some embodiments, the device 206 is an accelerometer for measuring linear acceleration. In some embodiments, the device 206 is a gyroscope for measuring angular velocity. In some embodiments, the device 206 has similar configuration as the device 101 h of the semiconductor structure 100 as described above or illustrated in FIG. 1.

In some embodiments, the interface 207 is disposed within the dielectric layer 203 or the conductive structure 204. In some embodiments, the interface 207 is at least partially across the dielectric layer 203. In some embodiments, the interface 207 is at least partially across the conductive structure 204. In some embodiments, the interface 207 is extended from the sidewall 203 c of the dielectric layer 203 towards the chamber 205. In some embodiments, the interface 207 is substantially orthogonal to the sidewall 203 c of the dielectric layer 203. In some embodiments, the interface 207 at least partially surrounds the chamber 205. In some embodiments, the interface 207 divides the dielectric layer 203 into an upper portion 203 a and a lower portion 203 b. In some embodiments, the interface 207 divides the conductive structure 204 into an upper portion 204 a and a lower portion 204 b. In some embodiments, the interface 207 is identifiable or visible under an electromagnetic radiation with a particular range of wavelength.

In the present disclosure, a method of manufacturing a semiconductor structure (100 or 200) is also disclosed. In some embodiments, the semiconductor structure (100 or 200) is formed by a method 300. The method 300 includes a number of operations and the description and illustration are not deemed as a limitation as the sequence of the operations. FIG. 3 is an embodiment of the method 300 of manufacturing the semiconductor structure (100 or 200). The method 300 includes a number of operations (301, 302, 303 and 304).

In operation 301, a first substrate 101 is received or provided as shown in FIG. 3A. In some embodiments, the first substrate 101 includes a first substrate layer 101 a, a first dielectric layer 101 b, a first conductive structure 101 c, a cavity 101 g and a device 101 h. In some embodiments, the first dielectric layer 101 b is disposed over the first substrate layer 101 a. In some embodiments, the first conductive structure 101 c is surrounded by the first dielectric layer 101 b. In some embodiments, the first conductive structure 101 c is at least partially exposed from the first dielectric layer 101 b. In some embodiments, the first substrate 101, the first substrate layer 101 a, the first dielectric layer 101 b, the first conductive structure 101 c, the cavity 101 g and the device 101 h have similar configurations as in the semiconductor structure 100 described above or illustrated in FIG. 1 or 2.

In operation 302, a second substrate 102 is received or provided as shown in FIG. 3B. In some embodiments, the second substrate 102 includes a second substrate layer 102 a, a second dielectric layer 102 b and a second conductive structure 102 c. In some embodiments, the second dielectric layer 102 b is disposed over the second substrate layer 102 a. In some embodiments, the second conductive structure 102 c is surrounded by the second dielectric layer 102 b. In some embodiments, the second conductive structure 102 c is at least partially exposed from the second dielectric layer 102 b. In some embodiments, the second substrate 102, the second substrate layer 102 a, the second dielectric layer 102 b and the second conductive structure 102 c have similar configurations as in the semiconductor structure 100 described above or illustrated in FIG. 1 or 2.

In operation 303, the first dielectric layer 101 b is bonded with the second dielectric layer 102 b as shown in FIG. 3C or 3D. In some embodiments, the second substrate 102 is flipped and bonded over the first substrate 101. In some embodiments, the first substrate 101 is aligned with the second substrate 102. In some embodiments, the first dielectric layer 101 b is aligned with the second dielectric layer 102 b. In some embodiments, the first dielectric layer 101 b is permanently bonded with the second dielectric layer 102 b. In some embodiments, an interface 207 is formed between the first dielectric layer 101 b and the second dielectric layer 102 b when the first dielectric layer 101 b is bonded with the second dielectric layer 102 b.

In some embodiments, the first dielectric layer 101 b is bonded with the second dielectric layer 102 b by direct bonding, fusion bonding operations or any other suitable operations. In some embodiments, the bonding of the first dielectric layer 101 b with the second dielectric layer 102 b is operated under a temperature of less than about 250° C. In some embodiments, the temperature is less than about 400° C. In some embodiments, the temperature is about 200° C. to about 300° C. In some embodiments, the first dielectric layer 101 b can be bonded with the second dielectric layer 102 b without an application of an external force over the first substrate 101 or the second substrate 102. In some embodiments, a compressive force of less than about 1000N is applied over the first substrate 101 or the second substrate 102 upon bonding the first dielectric layer 101 b with the second dielectric layer 102 b. In some embodiments, the compressive force is less than 30000N. Since the bonding of the first dielectric layer 101 b with the second dielectric layer 102 b is operated at a low temperature (for example, less than 250° C.) and no or small compressive force is applied over the first substrate 101 or the second substrate 102 during the bonding operations, damage on the first substrate 101 and the second substrate 102 could be minimized or prevented.

In operation 304, the first conductive structure 101 c is bonded with the second conductive structure 102 c as shown in FIG. 3C or 3D. In some embodiments, the second substrate 102 is flipped and bonded over the first substrate 101. In some embodiments, the first substrate 101 is aligned with the second substrate 102. In some embodiments, the first conductive structure 101 c is aligned with the second conductive structure 102 c. In some embodiments, the first conductive structure 101 c is permanently bonded with the second conductive structure 102 c. In some embodiments, the interface 207 is formed between the first conductive structure 101 c and the second conductive structure 102 c when the first conductive structure 101 c is bonded with the second conductive structure 102 c.

In some embodiments, the first conductive structure 101 c is bonded with the second conductive structure 102 c by direct bonding, fusion bonding operations or any other suitable operations. In some embodiments, the bonding of the first conductive structure 101 c with the second conductive structure 102 c is operated under a temperature of less than about 250° C. In some embodiments, the temperature is less than about 400° C. In some embodiments, the temperature is about 200° C. to about 300° C. In some embodiments, the first conductive structure 101 c can be bonded with the second conductive structure 102 c without an application of an external force over the first substrate 101 or the second substrate 102. In some embodiments, a compressive force of less than about 1000N is applied over the first substrate 101 or the second substrate 102 upon bonding the first conductive structure 101 c with the second conductive structure 102 c. In some embodiments, the compressive force is less than 30000N. Since the bonding of the first conductive structure 101 c with the second conductive structure 102 c is operated at a low temperature (for example, less than 250° C.) and no or small compressive force is applied over the first substrate 101 or the second substrate 102 during the bonding operations, damage on the first substrate 101 and the second substrate 102 could be minimized or prevented.

In some embodiments, the operation 303 and the operation 304 are performed simultaneously, that the bonding of the first dielectric layer 101 b with the second dielectric layer 102 b and the bonding of the first conductive structure 101 c with the second conductive structure 102 c are performed simultaneously. In some embodiments, the semiconductor structure (100 or 200) as shown in FIG. 3C or 3D is formed. In some embodiments, the semiconductor structure 100 in FIG. 3C has similar configuration as the semiconductor structure 100 in FIG. 1. In some embodiments, the semiconductor structure 200 in FIG. 3D has similar configuration as the semiconductor structure 200 in FIG. 2.

In the present disclosure, a method of manufacturing a semiconductor structure (100 or 200) is also disclosed. In some embodiments, the semiconductor structure (100 or 200) is formed by a method 400. FIG. 4 is an embodiment of the method 400 of manufacturing the semiconductor structure (100 or 200). The method 400 includes a number of operations (401, 402, 403, 404, 405, 406, 407 and 408).

In operation 401, a first substrate layer 101 a is received or provided as shown in FIG. 4A. In some embodiments, the first substrate layer 101 a includes a cavity 101 g disposed within the first substrate layer 101 a. In some embodiments, the first substrate layer 101 a includes a first silicon substrate, a second silicon substrate and an oxide layer disposed between the first silicon substrate and the second silicon substrate. In some embodiments, the first substrate layer 101 a having the cavity 101 g within the first substrate layer 101 a is formed by removing a portion of the first silicon substrate to form the cavity 101 g, disposing the oxide layer over the first silicon substrate and disposing the second silicon substrate over the oxide layer to cover the cavity 101 g. In some embodiments, the portion of the first substrate layer 101 a is removed by photolithography, etching or other suitable operations. In some embodiments, the first silicon substrate is bonded with the second silicon substrate through the oxide layer, that the second silicon substrate is bonded with the oxide layer by fusion bonding or any other suitable operations. In some embodiments, a thickness of the second silicon substrate is thinned down by backside grinding, etching or any other suitable operations.

In operation 402, a first dielectric layer 101 b is disposed over the first substrate layer 101 a as shown in FIG. 4B. In some embodiments, the first dielectric layer 101 b is disposed over the first substrate layer 101 a by deposition or any other suitable operations. In some embodiments, the first dielectric layer 101 b is patterned by removing a portion of the first dielectric layer 101 b. In some embodiments, the portion of the first dielectric layer 101 b is removed by etching or any other suitable operations. In some embodiments, the first substrate layer 101 a is partially exposed from the first dielectric layer 101 b. IN some embodiments, the first dielectric layer 101 b includes a first recess 101 i exposing a portion of the first substrate layer 101 a. In some embodiments, the first dielectric layer 101 b has similar configuration as described above or illustrated in FIG. 1 or 2.

In operation 403, a first conductive structure 101 c is formed as shown in FIG. 4C. In some embodiments, the first conductive structure 101 c is formed by damascene operations. In some embodiments, the first conductive structure 101 c is formed by disposing a conductive material such as copper over the first dielectric layer 101 b, filling the first recess 101 i by the conductive material and removing the excess conductive material on the first dielectric layer 101 b. In some embodiments, the conductive material is disposed by electroplating, sputtering or any other suitable operations. In some embodiments, the excess conductive material is removed by chemical mechanical planarization (CMP) or any other suitable operations. In some embodiments, a barrier layer such as titanium nitride and a seed layer such as copper are disposed conformal to the first recess 101 i and a surface of the first dielectric layer 101 b before disposing the conductive material.

In operation 404, a photo resist 410 is disposed over the first dielectric layer 101 b as shown in FIG. 4D. In some embodiments, the photo resist 410 is patterned to become a photomask. In some embodiments, the photo resist 410 is patterned by deposition and photolithography or any other suitable operations. In some embodiments, the photo resist 410 includes a second recess 410 a exposing a portion of the first dielectric layer 101 b.

In operation 405, a device 101 h is formed as shown in FIG. 4E or 4F. In some embodiments as shown in FIG. 4E, the first dielectric layer 101 b exposed from the photo resist 410 and a portion of the first substrate layer 101 a under the second recess 410 a are removed by etching or any other suitable operations to form the device 101 h. In some embodiments, the device 101 h is formed by removing several portions of the first substrate layer 101 a. In some embodiments, the device 101 h is disposed within the cavity 101 g. In some embodiments, as shown in FIG. 4F, the photo resist 410 is removed by etching, stripping or any other suitable operations after the formation of the device 101 h. In some embodiments, the device 101 h and the cavity 101 g have similar configuration as described above or illustrated in FIG. 1 or 2. In some embodiments, the first substrate 101 is formed as shown in FIG. 4F. In some embodiments, the first substrate 101 has similar configuration as described above or illustrated in FIG. 1 or 2.

In operation 406, a second substrate 102 is received or provided as shown in FIG. 4G. In some embodiments, the operation 406 is similar to the operation 302 as described above or illustrated in FIG. 3B.

In operation 407, the first dielectric layer 101 b of the first substrate 101 is bonded with a second dielectric layer 102 b of the second substrate 102 as shown in FIG. 4H or 4I. In some embodiments, the operation 407 is similar to the operation 303 as described above or illustrated in FIG. 3C or 3D.

In operation 408, the first conductive structure 101 c is bonded with a second conductive structure 102 c of the second substrate 102 as shown in FIG. 4H or 4I. In some embodiments, the operation 408 is similar to the operation 304 as described above or illustrated in FIG. 3C or 3D.

In some embodiments, the operation 407 and the operation 408 are performed simultaneously. In some embodiments, the cavity 101 g or the chamber 205 is sealed after the operation 407 and the operation 408. In some embodiments, the semiconductor structure (100 or 200) as shown in FIG. 4H or 4I is formed after the operation 407 and the operation 408. In some embodiments, the semiconductor structure (100 or 200) has similar configuration as described above or illustrated in FIG. 1 or 2.

The present disclosure is directed to a semiconductor structure including a substrate bonded with another substrate under a low temperature while without a high compressive force. Each substrate includes a dielectric layer and a conductive structure. The dielectric layers of substrates are bonded with each other, and the conductive structures of substrates are bonded with each other. Such direct bonding or fusion bonding does not require high temperature and high compressive force over the substrates, therefore the semiconductor structure would not be damaged during bonding operations. A reliability of the semiconductor structure is improved.

In some embodiments, a semiconductor structure includes a first substrate including a cavity extended into the first substrate, a device disposed within the cavity, a first dielectric layer disposed over the first substrate and a first conductive structure surrounded by the first dielectric layer; and a second substrate including a second dielectric layer disposed over the second substrate and a second conductive structure surrounded by the second dielectric layer, wherein the first conductive structure is bonded with the second conductive structure and the first dielectric layer is bonded with the second dielectric layer to seal the cavity.

In some embodiments, the first conductive structure is aligned with the second conductive structure, or the first substrate is aligned with the second substrate. In some embodiments, the first conductive structure is complementary to the second conductive structure. In some embodiments, a top surface of the first conductive structure is at a same level as a top surface of the first dielectric layer, or a top surface of the second conductive structure is a same level as a top surface of the second dielectric layer. In some embodiments, the cavity is enclosed by the first substrate, the first dielectric layer and the second dielectric layer. In some embodiments, the first conductive structure is extended along a periphery of the first substrate, or the second conductive structure is extended along a periphery of the second substrate. In some embodiments, the first conductive structure or the second conductive structure is in a partially closed loop or in a ring shape. In some embodiments, the first conductive structure or the second conductive structure is electrically connected with a circuitry disposed over the second substrate. In some embodiments, the first conductive structure and the second conductive structure include copper, and the first dielectric layer and the second dielectric layer include oxide or nitride. In some embodiments, the device is an accelerometer or includes a proof mass. In some embodiments, the cavity is in vacuum.

In some embodiments, a semiconductor structure, comprising: a first substrate; a second substrate disposed opposite to the first substrate; a dielectric layer disposed between the first substrate and the second substrate; a conductive structure disposed within the dielectric layer; a chamber extended from the first substrate to the dielectric layer and enclosed by the first substrate and the dielectric layer; and a device disposed within the chamber, wherein an interface is disposed within the dielectric layer or the conductive structure, and is extended from a sidewall of the dielectric layer towards the chamber and at least partially across the dielectric layer or the conductive structure.

In some embodiments, the interface is substantially orthogonal to the sidewall of the dielectric layer. In some embodiments, the interface divides the dielectric layer into an upper portion and a lower portion, or the interface divides the conductive structure into an upper portion and a lower portion. In some embodiments, the interface at least partially surrounds the chamber. In some embodiments, the chamber is hermetic.

In some embodiments, a method of manufacturing a semiconductor structure, comprising: receiving a first substrate including a first dielectric layer disposed over the first substrate and a first conductive structure surrounded by the first dielectric layer; receiving a second substrate including a second dielectric layer disposed over the second substrate and a second conductive structure surrounded by the second dielectric layer; bonding the first dielectric layer with the second dielectric layer; and bonding the first conductive structure with the second conductive structure.

In some embodiments, the bonding the first dielectric layer with the second dielectric layer and the bonding the first conductive structure with the second conductive structure are performed simultaneously. In some embodiments, the bonding the first dielectric layer with the second dielectric layer and the bonding the first conductive structure with the second conductive structure are operated under a temperature of less than about 250° C. In some embodiments, the first dielectric layer is bonded with the second dielectric layer by fusion bonding operations, or the first conductive structure is bonded with the second conductive structure by fusion bonding operations.

The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure. 

1. A semiconductor structure, comprising: a first substrate including a cavity extended into the first substrate, a device disposed within the cavity, a first dielectric layer disposed over the first substrate and a first conductive structure surrounded by the first dielectric layer; and a second substrate including a second dielectric layer disposed over the second substrate and a second conductive structure surrounded by the second dielectric layer, wherein the first conductive structure is interfaced with the second conductive structure and the first dielectric layer is interfaced with the second dielectric layer to seal the cavity.
 2. The semiconductor structure of claim 1, wherein the first conductive structure is aligned with the second conductive structure, or the first substrate is aligned with the second substrate.
 3. The semiconductor structure of claim 1, wherein the first conductive structure is complementary to the second conductive structure.
 4. The semiconductor structure of claim 1, wherein a top surface of the first conductive structure is at a same level as a top surface of the first dielectric layer, or a top surface of the second conductive structure is a same level as a top surface of the second dielectric layer.
 5. The semiconductor structure of claim 1, wherein the cavity is enclosed by the first substrate, the first dielectric layer and the second dielectric layer.
 6. The semiconductor structure of claim 1, wherein the first conductive structure is extended along a periphery of the first substrate, or the second conductive structure is extended along a periphery of the second substrate.
 7. The semiconductor structure of claim 1, wherein the first conductive structure or the second conductive structure is in a partially closed loop or in a ring shape.
 8. The semiconductor structure of claim 1, wherein the first conductive structure or the second conductive structure is electrically connected with a circuitry disposed over the second substrate.
 9. The semiconductor structure of claim 1, wherein the first conductive structure and the second conductive structure include copper, and the first dielectric layer and the second dielectric layer include oxide or nitride.
 10. The semiconductor structure of claim 1, wherein the device is an accelerometer or includes a proof mass.
 11. The semiconductor structure of claim 1, wherein the cavity is in vacuum.
 12. A semiconductor structure, comprising: a first substrate; a second substrate disposed opposite to the first substrate; a dielectric layer disposed between the first substrate and the second substrate; a conductive structure disposed within the dielectric layer; a chamber extended from the first substrate to the dielectric layer and enclosed by the first substrate and the dielectric layer; and a device disposed within the chamber, wherein an interface is disposed within the dielectric layer and the conductive structure, and is extended from a sidewall of the dielectric layer towards the chamber and at least partially across the dielectric layer and the conductive structure.
 13. The semiconductor structure of claim 12, wherein the interface is substantially orthogonal to the sidewall of the dielectric layer.
 14. The semiconductor structure of claim 12, wherein the interface divides the dielectric layer into an upper portion and a lower portion, or the interface divides the conductive structure into an upper portion and a lower portion.
 15. The semiconductor structure of claim 12, wherein the interface at least partially surrounds the chamber.
 16. The semiconductor structure of claim 12, wherein the chamber is hermetic. 17-20. (canceled)
 21. A semiconductor structure, comprising: a first substrate including a cavity extended into the first substrate, a MEMS device disposed within the cavity, a first dielectric layer disposed over the first substrate, and a first conductive structure at least partially exposed from the first dielectric layer; and a second substrate including a second dielectric layer disposed over the second substrate and a second conductive structure at least partially exposed from the second dielectric layer, wherein the first conductive structure exposed from the first dielectric layer is interfaced with the second conductive structure exposed from the second dielectric layer, and the first dielectric layer is interfaced with the second dielectric layer.
 22. The semiconductor structure of claim 21, wherein a first interface between the first conductive structure and the second conductive structure is at substantially same level as a second interface between the first dielectric layer and the second dielectric layer.
 23. The semiconductor structure of claim 21, wherein the first conductive structure is contacted with the second conductive structure.
 24. The semiconductor structure of claim 21, wherein the cavity is enclosed by the first conductive structure or the second conductive structure. 